Routing to multiple uplinks

Am I right in assuming that you're establishing application-layer sessions to two hosts with two different IP addresses (outside of your control) which provide (close to) identical services? If so, there's not much you can do outside of the application itself (at least if you want a semi-robust solution).
You could try (reverse) load balancer, but even then the application session would have to be disconnected before being switched over to the other host.
> As stated before Path A and Path B are two distinct paths they do however
> provide identical services but application state is not preserved. A new
> session and state must be established if a user decides to switch between
> paths.
Ivan Pepelnjak
blog.ioshints.info / www.ioshints.info